Water pump for vehicle

ABSTRACT

The present disclosure provides a water pump for a vehicle including an impeller with an impeller discharging port configured to pump and discharge coolant, a shroud movably installed to open and close the impeller discharging port, a first pushing unit configured to push the shroud in a direction of opening the impeller discharging port, and a second pushing unit configured to push the shroud in a direction of closing the impeller discharging port.

CROSS-REFERENCE TO RELATED APPLICATION

The-present application claims priority to and the benefit of KoreanPatent Application No. 10-2017-0174098 filed on Dec. 18, 2017, which isincorporated herein by reference in its entirety.

FIELD

The present disclosure relates to a water pump for a vehicle, and moreparticularly, a water pump for a vehicle capable of controlling adischarge flow rate in multiple stages.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Generally, a water pump used in a vehicle is a device for improving thecooling efficiency of the engine by forcibly circulating the coolant ofthe engine. It may be divided into a mechanical water pump whichdirectly receives rotational drive power from the engine to be driven inproportion to the number of revolutions of the engine and a variable orelectric water pump which is operated through a separate drive sourcesuch as a motor without directly receiving rotational power from theengine.

Since the mechanical water pump is disadvantageous in terms of energyefficiency and fuel efficiency because it cannot control variously thedriving mode of the water pump in accordance with the driving state ofthe engine and the vehicle, the variable water pumps have been recentlyapplied to improve fuel efficiency, and so on, even at the expense ofrising costs.

Various methods have been used to control the discharge flow rate ofvariable water pump to various discharge modes.

For example, a vacuum type water pump is a structure that adjusts theimpeller outlet by operating the slide with a negative pressure. It isadvantageous in terms of layout and has a simple control structure.

The water pump of the intermediate wheel type is a structure thatcontrols the rotation of the pulley by moving the position of theintermediate wheel through a built-in actuator, which is disadvantageousto durability due to slip and abrasion, and or the like.

Furthermore, an electronic clutch type water pump, which controls therotation of the impeller through an incorporated clutch, is advantageousin terms of layout but has a complicated drawback, and a variable waterpump, which controls the speed of the pump by controlling the connectionor disconnection of a pulley and a drive shaft through permanent magnet,has been usually applied to commercial vehicle, but it is difficult toprecisely control the intensity of permanent magnet and since the slipin the magnetic field requires radiating fins, which makes the structurethereof complicate and disadvantage in terms of cost.

SUMMARY

The present disclosure provides a water pump for a vehicle capable ofreducing the weight and cost by simple structure and preciselycontrolling the flow rate discharged from the water pump in multiplesteps.

A water pump for a vehicle in one form of the present disclosure mayinclude, an impeller with an impeller discharging port pumping anddischarging coolant, a shroud movably installed to open and close theimpeller discharging port, a first pushing unit configured to push theshroud in a direction of opening the impeller discharging port, and asecond pushing unit configured to push the shroud in a direction ofclosing the impeller discharging port.

A drive shaft may be installed at the impeller and a pulley may beconnected with the drive shaft.

The shroud may be movably installed in the axial direction along thedrive shaft.

The first pushing means may include a spring disposed between theimpeller and the shroud.

The second pushing unit may include a wax being connected with theshroud through a pushrod and volume-expanding or contracting dependingon the supplied heat amount, and a heater selectively supplying heat toa wax.

The heater may be connected to the engine control unit to be controlledby the operating signal of the engine control unit.

The engine control unit may be to apply an operating signal to theheater so that the heater heats up to the wax when the engine warms up.

The engine control unit may apply an operating signal to the heatercorresponding to the rotation speed of the engine, the load, and theambient temperature.

In accordance with a water pump for a vehicle in another form of thepresent disclosure, the heater is operated according to the controlsignal of the engine control unit to control the amount of heat suppliedto the wax, so that the opening of the impeller outlet through theshroud supported by the spring and the discharge flow rate of the waterpump can be precisely controlled in a stepwise manner.

By controlling the shroud to adjust the impeller outlet through only thewax and heater, the control structure can be simplified and weight andcost can be saved, and durability can be improved because there is nofriction element.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

In order that the disclosure may be well understood, there will now bedescribed various forms thereof, given by way of example, referencebeing made to the accompanying drawings, in which:

FIG. 1 is an example of a coolant circulation system for a vehicle towhich a water pump is applied;

FIG. 2 is an operating cross-sectional view when the water pump for thevehicle does not discharge the flow rate;

FIG. 3 is an operating cross-sectional view when the water pump for thevehicle discharges the flow rate; and

FIG. 4 is an operating cross-sectional view when the water pump for thevehicle discharges the maximum flow rate.

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

While the disclosure will be described in conjunction with exemplaryforms, it will be understood that present description is not intended tolimit the disclosure to those exemplary forms. On the contrary, thedisclosure is intended to cover not only the exemplary forms, but alsovarious alternatives, modifications, equivalents and other exemplaryforms, which may be included within the spirit and scope of thedisclosure as defined by the appended claims. The terminology usedherein is for the purpose of describing particular forms only and is notintended to be limiting of the disclosure. As used herein, the singularforms “a”, “an” and “the” are intended to include the plural forms aswell, unless the context clearly indicates otherwise. It will be furtherunderstood that the terms “comprises” and/or “comprising,” when used inthis specification, specify the presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof. As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. For example, in order to make thedescription of the present disclosure clear, unrelated parts are notshown and, the thicknesses of layers and regions are exaggerated forclarity. Further, when it is stated that a layer is “on” another layeror substrate, the layer may be directly on another layer or substrate ora third layer may be disposed there between. It is understood that theterm “vehicle” or “vehicular” or other similar term as used herein isinclusive of motor vehicle in general such as passenger automobilesincluding sports utility vehicles (SUV), buses, trucks, variouscommercial vehicles, watercraft including a variety of boats, ships,aircraft, and the like and includes hybrid vehicles, electric vehicles,combustion, plug-in hybrid electric vehicles, hydrogen-powered vehiclesand other alternative fuel vehicles (e.g. fuels derived from resourcesother than petroleum). Some forms of the present disclosure will now bedescribed in detail with reference to the accompanying drawing.Referring to FIG. 1, an engine coolant circulation system for a vehicleto which a water pump for a vehicle in some forms of the presentdisclosure is applied may be configured as follows.

A water pump for a vehicle 1 in some forms of the present disclosurepressurizes and pumps coolant to supply it to a cylinder block 2 of anengine; the coolant cools a cylinder block 2 and a cylinder head 3 andthen, discharged from the cylinder head 3 to be flowed into a directionadjusting valve 4.

Some coolant flowed into the direction adjusting valve 4 is heated by aheater 6 via a low pressure EGR (Exhaust Gas Recirculation) cooler 5,and then flows into the water pump 1 and some coolant flowed back to thewater pump 1 via an EGR valve 7.

Some coolant flowed into the direction adjusting valve 4 is injectedinto a reservoir tank 8 and stored in the reservoir tank 8 or suppliedto a radiator 9 to be cooled and then flows into a thermostat valve 10,and the coolant passing through the thermostat valve 10 is again flowedinto the water pump 1.

Furthermore, some coolant flowed into the direction adjusting valve 4 isflowed into the water pump 1 via an ATF warmer 11, an oil cooler 12 anda high pressure EGR cooler 13, and the coolant discharged from thereservoir tank 8 flows into the thermostat valve 10.

The water pump 1 in some forms of the present disclosure applied to thecoolant circulation system as described above may include, as shown inFIG. 3, an impeller 32 for pressurizing and pumping the coolant anddischarging through an impeller discharging port 31, a drive shaft 33thereof, and a pulley 34 for supplying rotational power to the impellerdrive shaft 33.

A bearing 35 may be mounted at the outer circumference of the impellerdrive shaft 33 to support the impeller drive shaft 33 to be rotatable.

The impeller discharge port 31 may be closed or partially open or fullyopen by a shroud 36 which may be movably mounted along the impellerdrive shaft 33.

A spring 37 may be installed as a first pushing means between theimpeller 32 and the shroud 36 to elastically push the shroud 36 in adirection to open the impeller discharging port 31. The spring 37 may beseated on and supported by a spring seat 38.

A second pushing means may be provided opposite the spring 37 to pushthe shroud 36 in a direction closing the impeller discharging port 31.

The second pushing means may include a wax 40 that volumetricallyexpands or contracts according to the calorie supplied with the shroud36 via a pushrod 39 and a heater 41 that does not supply or supply heatto the wax 40.

The heater 41 may be connected to an engine control unit ECU, and itsoperation may be controlled according to the control signal of theengine control unit ECU.

The heater 41 and the wax 34 may be connected to a heat conducting wire42 or a heat conducting rod.

The engine control unit The ECU can judge the driving state of theengine and also judge the driving state of the vehicle through varioussensors.

The operation state of FIG. 2 shows the state that the engine controlunit ECU applies an operation signal to the heater 41, and the heatgenerated in the heater 41 is supplied to the wax 34 through the heatconducting wire 42, so that the wax 34 is expanded to the maximum, thespring 37 is compressed by the shroud 36.

The pushrod 39 pushes the shroud 36 according to the volume expansion ofthe wax 34, as shown by the arrows, so that the shroud 36 closes theimpeller discharging port 31 to prevent the circulation of the coolantthrough the water pump 1 and the coolant temperature rises quickly,thereby shortening the warm-up time of the engine and improving fuelefficiency.

When the coolant temperature rises appropriately after the warm-up ofthe engine, the engine control unit ECU controls the operating signal ofthe heater 41 to control the amount of heat generated by the heater.

Then, as shown in FIG. 3, the position of the shroud 36 is adjusted atthe point where the elastic restoring force of the spring 37 and theexpansion force of the wax 40 are in equilibrium, the impellerdischarging port 31 is opened to the partial by the shroud 36, and thecoolant circulation is performed while the water pump 1 pressurizes anddischarges the coolant.

The engine control unit ECU can control the heat amount generated by theheater 41 by controlling the operation signal applied to the heater 41according to the predetermined map or the program in consideration ofthe factors such as the rotation speed of the engine, the load and theoutside temperature. For example, in the high load operating range ofthe engine, the coolant discharge flow rate is increased and in the lowload operating range of the engine, the discharge flow rate is reducedto improve the fuel efficiency.

On the other hand, when the coolant temperature of the engine rises tobecome hot, the engine control unit ECU interrupts the operating signalapplied to the heater 41, and accordingly the shroud 36 is pushed in thedirection of opening the impeller discharging port 31 to fully open theimpeller discharging port 31, so that the coolant circulates rapidlyalong the circulating system.

In some forms of the present disclosure, although the spring areexemplified as the first pushing means and the wax and the heater as thesecond pushing means, a solenoid valve, a clutch or the like can bereplaced.

The description of the disclosure is merely exemplary in nature and,thus, variations that do not depart from the substance of the disclosureare intended to be within the scope of the disclosure. Such variationsare not to be regarded as a departure from the spirit and scope of thedisclosure.

DESCRIPTION OF SYMBOLS

-   1: water pump-   2: cylinder block-   3: cylinder head-   4: direction adjusting valve-   5: low pressure EGR cooler-   6: heater-   7: EGR valve-   8: reservoir tank-   9: radiator-   10: thermostat valve-   11: ATF warmer-   12: oil cooler-   13: high pressure EGR cooler-   31: impeller discharging outlet-   32: impeller-   33: drive shaft-   34: pulley-   35: bearing-   36: shroud-   37: spring-   38: spring seat-   39: pushrod-   40: wax-   41: heater

What is claimed is:
 1. A water pump for a vehicle, comprising: animpeller with an impeller discharging port that is configured to pumpand to discharge coolant; a shroud movably installed and configured toopen and to close the impeller discharging port; a first pushing unitconfigured to push the shroud in a direction of opening the impellerdischarging port; and a second pushing unit configured to push theshroud in a direction of closing the impeller discharging port.
 2. Thewater pump for the vehicle of claim 1, wherein: a drive shaft isprovided in the impeller; and a pulley is connected with the driveshaft.
 3. The water pump for the vehicle of claim 2, wherein the shroudis movably installed in an axial direction along the drive shaft.
 4. Thewater pump for the vehicle of claim 1, wherein the first pushing unitcomprises a spring disposed between the impeller and the shroud.
 5. Thewater pump for the vehicle of claim 1, wherein the second pushing devicecomprises: a wax connected with the shroud through a pushrod, the waxconfigured to expand or contract depending on a heat amount; and aheater selectively configured to supply heat to the wax.
 6. The waterpump for the vehicle of claim 5, wherein the heater is connected to anengine control unit and controlled by an operating signal of the enginecontrol unit.
 7. The water pump for the vehicle of claim 6, wherein theengine control unit is configured to apply the operating signal to theheater such that the heater heats up the wax when an engine warms up. 8.The water pump for the vehicle of claim 6, wherein the engine controlunit is configured to apply the operating signal to the heatercorresponding to a rotation speed of the engine, a load, and an ambienttemperature.